"of all the things, i had to forget that would be easiest " ? why should the narrator said this ?

Considering all the things that the author had to forget, the address would be the easiest because there were memories of times, people and things which she would have to forget and these would be much more difficult than a mere address. She did not want to remember the objects that were linked in her memory to familiar times because these did not belong to that place anymore and seemed unfamiliar. Thus,creating a jarring effect in her mind. She could not have taken those things even though they belonged to her mother because they had lost their value and she did not have a place to keep them. So she wanted to forget them but one cannot so easily forget things of the past.